Using a datum or a benchmark, features or objects on the landscape can be mapped or tied-in by direction (azimuth or bearing) in conjunction with distance. Doing so is not unlike what is done by triangulation, but in this case an instrument capable of measuring horizontal angles is used and it is not nessary to use more than one vector to tie-in each point. The procedure is quite simple.
Standing at the datum, the fieldworker takes a reading on a feature using an instrument such as a Brunton Pocket Transit. He or she records the azimuth or bearing and then, using a tape measure, determines the distance of the object from the benchmark. Both pieces of data are recorded in the field note book--in tabular form on the left and graphic form on the right.
Created by William E. Doolittle. Last revised 14 December 2017